At her age and considering how this has had this type of effect on her R with boys, dating, M, etc......I think the "truth" is more important than you trying to protect her from pain. Listen, I am the world's worst at trying to shield my loved ones from things "I" think will hurt them. They are either too young, too old, sick, or some other thing that I find to shelter them.
You D apparently knows what is going on, so tell your H and I hope that the two of you can approach your D and tell her that from now on, you'll be upfront with her. If you & H can come together enough to allow D to ask questions then that would probably do a lot for her. If you don't know the answer to something she asks, the just tell her, "IDK".
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!
